Accessory Navicular



What is an Accessory Navicular?


An Accessory Navicular  (os navicularum or os tibiale externum) is an extra bone sitting beside the navicular. The accessory Navicular is engulfed by the tibialis posterior tendon and can also affect the spring ligament, both of which attach in the area. Accessory Navicular can range from pea sized to large walnut sized. They can be round, flat or partially attached to the main Navicular.

People with Accessory Navicular have low arches. Certain Accessory Navicular are vulnerable to injury so that the arch can become flatter and more painful. Later in life, patients with Accessory Navicular can develop tibialis posterior tendon dysfunction.

People with a painful Accessory Navicular have pain and swelling on the inside of the foot close to the ankle. Individuals with a painful accesory navicular have flattening of the  arch, and tired feet.

What is the Tibialis Posterior Tendon?

The Tibialis Posterior is a muscle that runs deep in the calf and its tendon inserts onto the arch of the foot. The tendon is one of the key arch supports along with several ligaments (and also the bones whose shape forms the arch of the foot).

Patients without a normal arch find that their foot feels very inefficient.


What are the treatment options?

A painful accessory Navicular can be treated in several ways:

  1. Insoles and stiff soled shoes such as walking boots or even custom shoes.

  2. Try a steroid injection into the most painful area under Ultrasound guidance and rest the foot in an Aircast Boot.

  3. Release the tight muscle in the back of the legs to allow the insoles to work better.

  4. Rebuild the arch of the foot through surgery by removing the accessory navicular, advancing/tightening the  tibialis posterior tendon, and surgery to release the tight gastrocnemius and keyhole surgery to realign the heel.


What can I expect on the day of surgery?

  • The surgery will normally be under a general anaesthetic.

  • This is an overnight stay surgery.

  • I will numb the ankle with local anaesthetic so that you will be comfortable when you wake.

  • There will be a bulky half plaster cast on your lower leg which you will keep clean and dry.

  • You will be given crutches or a frame and told not to weight bear.

What are the risks and complications?

The vast majority of patients do extremely well. A small group of patients need extra physio due to swelling or stiffness. . Complications include infection, blood clots (DVT), nerve damage, non-union, painful screws requiring removal, failure of repair.

When can I drive?

The best guide that you are safe to return to driving is that you are able to walk well without crutches and without a plaster or a boot. The usual time scale also depends on whether you had surgery on your right or left foot and whether you drive a manual or an automatic

  • Right side and all car types: 2 months

  • Left side and manual car: 2 months

  • Left side &automatic car: 2 weeks

How long should I take off work?

The time you require off from work depends on what type of job you do. The first two weeks of healing are critical and so you must have this time off work. Many people are able to work from home and so if you can avoid commuting in the first six - eight weeks, you will find that your ankle does better. If your employer can be flexible with your activity at work you may be able to do some lighter duties or reduced hours from 3 weeks onward. If you work on your feet all day, do a manual job, or are required to wear dress shoes you may need 8 weeks before you are back at work.

Clear Advice About DVT

A DVT is a Deep Vein Thrombosis or a blood clot in the leg. A blood clot occurs after surgery where patients are placed into plaster or a splint for about 2 in every 100 patients. You can help prevent a blood clot by keeping your knee moving. Keeping yourself hydrated is also helpful to prevent a DVT. Finally elevating your leg to the level of your heart will minimise the amount of swelling you have which will also help to prevent a DVT. You will be given blood thinners for the first two weeks when you at your least active.

We will discuss how best to prevent a DVT and for most patients we opt to use injections of  blood thinners for the first two weeks after surgery. After two weeks the risk is not completely gone however, you will be able to be more active. Most patients would rather stop blood thinners at that stage and monitor their leg for symptoms.


If you were to develop a DVT you would likely have some symptoms and so it is very helpful if know what to look for:

  • The leg (above the dressing/foot) would become hard, heavy, swollen, painful and/or red

  • If you were to have any of the above symptoms you would have to have a scan to look for a blood clot and then be treated with blood thinners

If the blood clot were to move to the lungs you would have a pulmonary embolism which is a medical emergency

  • The symptoms of a pulmonary embolism are breathless & chest pain- Call 911

The Recovery After Accessory Navicular Repair

Instructions 0-2 weeks

  1. Elevate Leg Above Heart most of the time

  2. Keep dry for two weeks

  3. Low-Molecular-Weight Heparin Injection daily for two weeks

  4. Non weight bearing in plaster back slab

  5. Move toes and knee


2 weeks in clinic

  • I will arrange to have your plaster & sutures removed

  • You will then be placed in a full plaster and instructed to be weight bearing for the next two weeks

  • Initially you will only place some weight through the plaster and some through crutches

  • Week on week you should find that you can put more weight through the plaster

  • Eventually you will take your weight fully through the plaster


4 weeks in clinic

  • I will remove your plaster and place you in an aircast boot

  • You will be allowed to remove the boot to sleep and bathe but you must wear the boot when standing and walking


6 weeks in clinic

  • I will send you for a X-rays of the ankle

  • Provided the X-rays show some healing you will be allowed to start to wean yourself from the removable Aircast boot

 Physiotherapy instructions once able to weightbear and remove the Aircast boot

  • Use the Boot for comfort but start to take small steps at home without the boot

  • Gradually use the boot less and less as comfort allows

  • Use Contrast bathing with bowls of hot and cold water. Place foot for 20 sec in cold and then alternate for 30 sec in hot. Do for 5 min.

  • Your physiotherapist can use other local modalities to reduce swelling

  • You may ice the ankle if this helps

  • Use a compression stocking and elevate the ankle above the heart to help swelling

  • Start to work on strengthening

    • Theraband Resistance

    • Cycling on stationary cycle

    • Swimming and Hydrotherapy

    • Work on developing an even gait

    • Progressing to double heel rises





  • You can go up and down on tiptoes in sets of 3, slowly and 15 reps in each

  • You can stand on a skipping rope and adjust your foot position

  • You can hold a DHR for 15 seconds

  • It can be difficult to progress to the next award level because the ankle will take double the weight when you move to lifting the good leg to lower only on the operated leg.

  • You are better to stay at the bronze award level but to add in a back pack with increasing weight as you feel ready for more

  • When you have done this for some time you will be ready to progress to the silver award level




  • May need to add weight in backpack on DHR to reach silver level

  • You go up on both feet but lift unoperated leg and lower slowly only on operated leg

  • 3 sets, working up to 15 reps in each

  • You can stand both feet on a wobble board

  • You can hold a solid DHR for 20 seconds




  • 3 sets, working up to 15 reps in each

  • You can stand on one foot on wobble board

  • You can hold a solid DHR for 40+ seconds

  • Many patients decide to finish physiotherapy when they have achieved this level



  • Progress to hopping in all directions

  • Double Hops

  • Gentle jogging to reintroduce running